Winter Chills and Rising Energy Bills
Winter has truly arrived. Several states — including Tasmania, Victoria, New South Wales, and southern Queensland – have had an ‘unusually’ cold start to winter this June, according to media reports. In fact, Sydney has endured its coldest first week of June in more than 30 years.
The onset of Winter also means the comeback of a familiar challenge – an increase in the cost of utility bills as building systems work overtime to maintain comfortable temperatures inside for building occupants.
Under normal circumstances, keeping energy costs down during the Winter months (and in Summer months as well) can be a challenge for most commercial building operators and facilities managers. The recent sharp spike in energy prices makes their job even harder.
Recent international events, world-wide supply chain issues and unique supply and demand dynamics in Australia’s gas market and electricity generation markets, has meant a steep and sudden rise in energy prices. Reports suggest the sharp increase is not a temporary spike, as most would like to believe, but that it will likely to stay high for the next couple of years.
The default approach many commecial building operators would take to tackle rising energy costs and keep their buildings warm this winter is to ensure their Heating, Ventilation and Air Conditioning system (HVAC) is well optimised and operating as efficiently as possible. That’s an important step in keeping utility costs as low as possible. There is however, another aspect to a building that many overlook when it comes to promoting energy efficiency and thermal comfort within buildings – the building itself!
What we mean by that is ‘Building Envelope‘and the role it plays in making the building more energy efficient in terms of reducing operating costs and enhancing occupancy comfort.
While some are quite familiar with what building envelope is, many might not have a complete understanding and how integral it is to increasing energy efficiency and keeping energy costs down. In this article, we’ll be discussing what building envelope entails and share a few tips and strategies on how to get it right.
Understanding Building Envelope
What is ‘Building Envelope?’
When we talk about building envelope some immediately think of Building Insulation and that they are both one in the same. They’re neither right nor wrong. Building insulation often refers to the thermal properties of the design and materials inside a building – the insulating materials between walls and inside empty spaces such as ceilings – such as: fiberglass, cellulose, mineral wool, polyurethane foam and polystyrene (styrofoam).
Whereas building envelope is a ‘whole of building’ view of the thermal or insulating properties of all the materials used on both the outside and the inside of a building. Building envelope is often used interchangeably with the word ‘Building sealing’, however building envelope is the more common term.
Seals around doors and windows, window films/tinting and reflective heat paint and of course insulation materials between walls and ceilings, are just a few examples of the many aspects to building envelope. The type of materials used, the size, thickness and quanity of doors and windows in a building, can influence how much heat is lost (‘Heat Loss’) or gained on either cold or hot days.
Infographic 1 will help explain what a building envelope is and what it incorporates.
Why is Heat Loss a Cause for Concern During Winters?
Heat loss is a major issue during winters. Heat loss occurs when heat escapes from a building to the outside, most commonly through the walls, roof, windows, floors, cracks, or gaps. Radiation, convection, and conduction are the most common causes of heat loss. According to the Second Law of Thermodynamics:
Heat flows naturally from regions of higher temperature to regions of lower temperature, but that it will not flow naturally the other way.
While heat loss is a natural occurrence, keep in mind that you are paying for the heat you are losing as a result of this process.
That is why architects and construction engineers design and construct buildings with materials that have insulating properties which slows down the transfer of heat (from both outside-in, and inside-out).
The more heat you lose, the longer and harder your HVAC system will have to work to maintain the desired temperature in your building. Not only would this increase your energy expenses, but it will also cause HVAC system to overwork, costing more to maintain and repair and reducing its useable life.
The Role of Building Envelope in Tackling Energy Loss During Winters
- During winter, the building envelope helps limit the heat transfer from inside to outside (Its role shifts during summer as the envelope keeps the cooled air within and the hot air outside during the summer months).
- The building envelope plays an important part in a structure’s energy efficiency because of the barrier it creates for heat transfer. Keeping heated or chilled air inside (and their opposites outside) uses less energy and saves money on heating and cooling.
Infographic 2 can further explain the importance of the building envelope.
Strategies to Improve Building Envelope’s Energy Efficiency
Several new building technologies, construction techniques, and operational tactics have been assisting building owners in achieving energy savings that were previously unattainable. Some of these innovations are completely new, while others are upgrades to established technologies.
These strategies not only help improve building envelope’s energy efficiency but also the occupant comfort in buildings. Let’s look at some of the successful and proven strategies.
Opting for Green Roofs
Green roofs are becoming an increasingly popular method of improving building envelope performance. One of the numerous advantages of green roofs is their capacity to preserve energy and reduce heating costs significantly during the winter months for those buildings that use them. By adding plants, shrubs, and grass to the tops of certain urban structures, they become more naturally insulated from the weather, lowering energy costs, surface temperatures, and stormwater pollution.
According to studies, green roofs can retain anywhere from 25% to 40% of the precipitation that falls throughout the winter months. This additional insulation can help immensely in relieving the strain of skyrocketing heating fuel expenses because these are the places of the highest heat loss during this time of year.
Investing in Smart Glass or Low-E Glass
Smart glass, sometimes known as ‘switchable glass’, is a type of glass that changes its light transmission capabilities when exposed to light, heat, or electricity. Its primary premise is that it transitions from clear to dark and back. While certain wavelengths of light are blocked, some light does pass through the glass. Controlling smart glass can be done manually or automatically if its integrated with smart building controls.
Smart Glass, which can be incorporated into a Building Management System, can help regulate the heat within a building during the winter months. A commercial establishment can forego using heavy, insulated curtains and use this type of glass instead. The glass adjusts the level of its tint according to its user’s preference. It can be programmed to allow for more radiance to fill areas that require more heat. It also allows for natural sunlight to flow into rooms to increase a building occupants’ visual comfort. Using Smart Glass also lowers HVAC costs and usage while boosting occupant comfort.
When it comes to Low-E glass, ‘Low-E’ (low emissivity) refers to a material’s capacity to radiate absorbed energy and limit heat transmission. This high-tech, nearly undetectable protective coating on the low-E glass works by blocking some wavelengths of light while allowing others to get through. A low-E coating reduces heat transfer through the glass by allowing light in while reflecting heat back to the source, improving thermal efficiency and helping to create a lighter, healthier house.
Thermal Facade, Vapour Barrier, and More
Research states that there are four particular aspects of a building envelope that make them highly energy-efficient. An energy-efficient building envelope will “have high thermal resistant materials in the facade of the building, use vapour barriers and are effective in vapour control, have efficient window and door seals, have effective airflow control to minimize infiltration of outdoor air,” according to the research. When it comes to increasing the thermal resistance of a building, increasing the thickness of the insulating material is considered to be the most practical and simple solution.
Some of the other expert-suggested strategies to get the building envelope right include:
- opting for less labour-intensive air sealing and less costly validation testing
- using more durable and lower-cost reflective roofing materials and coatings
Benefits of Good Building Envelope Can be Experienced Year-Around
A building envelope is not just important to increase energy efficiency during winter, but has benefits all year-around too. We should therefore be making use of all the opportunities to improve and maintain the building envelope in your commercial building.
To best guarantee the effectiveness of a building envelope, always consult with experts and have a well-thought-out plan in place to ensure that you have everything properly implemented. This will help make sure that your commercial building’s energy efficiency is optimised during winter and after – increasing your financial savings and sustainability efforts.
Ecosave on Improving Building Insulation and Energy Savings
Ecosave believes in engineering-based solutions to conserving heat (energy) and reducing overhead costs for building owners. There shouldn’t be shortcuts to energy savings and improving building insulation is an essential key to sustainability.
Ecosave can partner with your organisation to assess and evaluate your commercial building envelope as well as design and implement effective retrofit upgrades or renovations to key aspects of building envelope, including the optimisation and upgrades to HVAC and BMS for better control and efficient heating and cooling operations.
Let our specialists assist you with your energy savings enquiries by requesting a Free Call Back or phoning us at 1300 55 77 64 today!